Process for the manufacture of amino-steroids



United States Patent The present invention provides a new, simple process for the manufacture of amino-steroids, wherein a ketosteroid is reacted with an amine of the formula R1 H:N( JH-R' in which R represents hydrogen or a substituted or unsubstituted hydrocarbon radical, and R a substituted or unsubstituted aryl radicaland the arylideneaminosteroid formed as an intermediate is hydrolysed. The following partial formulae represent the process:

As will be seen from these formulae, the primarily formed 'imino compound of type A is rearranged into the arylideneamino compound B which latter on being hydrolysed yields the aminosteroid and the arylketone or -aldehyde respectively corresponding to the amine used. 1 As amine component may be used any desired amine ofthe above formula, above all a substituted or unsubstituted arylmethylamine such as a benzylamine, diphenylmethylamine, naphthylmethylamine which may be substituted in meta-position relatively to the aminomethyl' group, more especially in orthoor paraposition thereto,

by an alkoxy group, for example a methoxy group, a halogen atom, for example chlorine, or by a substituted or unsubstituted phenyl radical.

The reaction according to the invention of the ketosteroid with the amine is performed in a suitable solvent, for example'in an alcohol, more especially in an excess of amine, and in the presence of a condensing agent, for example in the presence of a strong inorganic or organic base, such as a hydroxide or an alcoholate of an alkali metal or alkaline earth metal, such as sodium hydroxide, potassium hydroxide, sodium ethylate, sodium methylate, a quaternary ammonium base, for example benzyl-trimethyl ammonium hydroxide. The reaction is advantageously performed with the exclusion of air, for example under nitrogen, at an elevated temperature, for example between about 100 and 200 C.

The hydrolytic cleavage of the arylideneamino-steroid formed is performed with an acid hydrolysing agent, such as a strong inorganic or organic acid, for example hydrochloric, sulfuric, perchloric acid or the like. This process yields the amino-steroids in the form of their salts many of which are relatively sparingly soluble; the free amine is prepared from the salt in as such known manner by alkalinisation with a strong base, such as ammonia, or a solution of sodium carbonate, sodium hydroxide or potassiumhydroxide. g 1

The keto-steroids used as starting materials are derived from the known steroid series, such as the cholestane, coprostane, ergostane, sitostane, spirostane, cho- 3,004,903 Patented Oct. 17, 1961 "ice lane, bisnorcholane, etiocholane, pregnane, allopreg'nane,

androstane, oestrane series, or from tetracyclic triterpenes (4:4:l4-trimethyl-steroids), for example from lanosterol. These starting materials contain one or several oxo groups in the positions 1, 2, 3, 4,6, 7, 11, 12, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24. Apart from the 0x0 groups they may contain any desired further substituents such as free or functionally converted (for example esterfied or etherified) hydroxyl groups; ketalized, such as acetalized or enolized oxo' groups; alkyl groups, such as methyl groups; or free or functionally converted car' These substituents may be contained in boxyl groups.

The

one or several of the afore-mentioned positions.

starting materials may be saturated inthe ring system The arylideneamino and amino-steroid compounds ob-' tained by the present process are biologically active themselves or can be used as intermediates for the preparation of biologically active compounds.

The compounds can be used as medicaments, for example in the form of pharmaceutical preparations which contain the active substance in admixture with a phar- ,maceutical organic or inorganic, solid or'liquid carrier 'suitable for enteral or parenteral administration. As

carriers such substances come into consideration as do not react with the new compounds, such as for instance water, gelatine, lactose, starch, magnesium stearate, talc,

vegetable oils, benzylalcohols, gums, polyalkylene gly- 'cols, cholesterol or other known carriers. Thepharmaceutical preparations can be in the form, for instance, of tablets or dragees or in liquid form as solutions, suspensions or emulsions. They may be sterilized and/or 1 contain auxiliary substances, such as preserving, stabilizing, wetting or emulsifying agents, salts for the modification of osmitic pressure or buffers. They may also contain other therapeutically useful substances. The preparations are obtained in the customary way.

The following examples illustrate the invention,

Example 1 500 mg. of cholestanone are dissolved in 2Ov cc. of

freshly distilled benzylamine, 3 grams of sodium methylate are added, and the whole is refluxedv for 47 hours. The solution is cooled, poured into an excess of. dilute hydrochloric acid (1:4) and kept for 1 hour at 7080 C. The reaction mixture is then cooled to room temperature, and the precipitated hydrochloride of 33A aminocholestane is suctioned off and thoroughly washed H with water and ether to remove traces of starting material The residue is dissolved in a small amount of methanol, and the solution is treated with solid 1 potassium hydroxide to produce a strongly alkaline re- The whole is diluted with water, taken up in'f ether, washed with water until neutral and dried over i.

and benzaldehyde.

action.

sodium sulfate. The ethereal solution is evaporated to yield 438 mg. of crude crystalline 31S-aminocholestane (M.P. 112 C. from acetone).

potassium hydroxide, and the precipitating free base is taken up in ether.

After having been recrystallized once from acetone, the product obtained in this manner melts at 100101 C,

The ethereal solution is washed 6 times with water, drier over sodium sulfate and evapof" 1' rated, to yield mg. of 3,8-dimethylamino-cholestane}l E Example 2 2 grams of allopregnane-Bfl-ol-ZO-one acetate are dissolved in 40 cc. of benzylamine and refluxed with 6 gramsof sodium methylate for 1-8 hoursunder nitrogen; To

hydrolyse the resulting 2Q benzylid'eneamino-allopregname-35401, thereaction mixture is cooled, mixed: with an excess of dilute hydrochloric acid and heated for 2' hours: at. 80 C. The water-insoluble hydrochloride of the 2TO-isomeric amines is filtered while cold and washed out with water and ether. The suspension of the hydrochlorides in methanol is' rendered alkaline with concentrated' ammonia and then taken upin ether. The ethereal solution; is washed with water until neutral, dried and then; evaporated, to yield 1.15 grams'of a crystallizate 7 10' grams of l l-keto-tigogeninare dissolved in 400 cc. of benzylamineiand' refluxed for 7 days, while being vibrated, with 40 grams of sodium methylate under nitrogen. The reaction mixture is poured into excess 'dilutehydnochloric acid, the'insoluble matter is filtered off, dissolved in methanol and again combined with the hydrochloric acid solution, which is then heated for 4 hours at- 80 C. The precipitated hydrochloride is filtered ofiand' freed from hydrochloric acid, starting material and benzaldehyde by being washed with water and ether. The methanolicsuspension of the salt is treated with solid potassium hydroxide, diluted with water, taken up inether and washed until neutral, to yield 5.241 grams of a crystalline base. This base is separated by chromato'graphy on alumina, to yield 1.54 grams of pure 1'15- amino-tigogenin melting at 182-183 C. [a] =56) and 1.62 grams of l'la-a'mino-tigogenin melting at 202- 203 C. ('[ci-] ''=-39).

Example 4' V A mixture of 5 grains of hecogenin acetate, 5- grams of sodium methylate, 50 cc. of benzylamine and 25 cc. of methanol is refluxedfor 24 hours and then kept overnight at room temperature. The benzylidene compound formed is hydrolyzed by being heated for 3 hours with excess aqueous hydrochloric acid. From the cooledmixture the hydrochloride of IZ-aminotigOgenin is obtained; by suction filtration and washing with water, ether and methylene chloride This latter product yields the base when an alcoholic solution thereof is treated with potassiurn' hydroxide and then worked up. The yield of crude ar'nin'e amounts to 1.590 grams. Repeated recrystallization from ether yieIGs'IZ-amino-tigogenin melting at 212'213C.

a Example 5 "5 grams of androstane 3)3-o1 -l7-one acetate are dis-Q solved in 70 cc. of benzylamine with the addition of 10 grams' of sodium methylate and refluxed overnight. To hydrolyse the 17-henzylideneamino-androst'ane 3B 01 formed, the. reaction; mixture: is 7 treated with excess aqueous hydrochloric acid (1:4), heated for 4 hours at 80 C. and then kept for .18 hours at room temperature.

The p'artially Water-insoluble hydrochloride is suctioned ofi, washed on' the filter with water and ether, and the base i'sliberat ed with concentrated ammonia and extracted with ether. The yield is 211 grams ofamorph'ous 17'-amino-androstane-3fl -ol. The aqueous washings are extracted by being shaken with ether and thus freed from benzaldehyde and starting material. Addition of solid potassium hydroxide (with cooling) liberates a further amount of the base and surplus benzylamine. From the mixture of l7-amino-androstane-3 3-o1 and benzylamine, obtained by shaking with ether and thorough washing of the filter residue with water, the benzylamine is removed 7 by. repeated evaporation in vacuo with water and benzene, to yield another l.3 gramsof l7-amino-3B hydroxy- Sa-andmstane. Total yield: 3.4 grams.

Example 6 5 grams of 1l-keto-allopregnane-3,8!ol-20-ethyleneketal acetate are dissolved in cc. of benzylamine, mixed with 20 grams of sodium ethylate and refluxed for 4 days under nitrogen.

The hydrolysis is conducted as described in Examples l-5. The acid aqueous solution is shaken with ether, to yield- 850 mg. of 1l:20-diketo-allopregnane-3B-o1. After 'alkalinisation with potassium hydroxide, shaking with etherand repeated evaporation with water and benzene (to remove the excess of benzylamine) crude 1l-amino-allopregnane-IiB-ol-ZO-one is obtained.

What is claimed is:

1. Process for the manufacture of amino-steroids, wherein a keto-steroid is reacted with an amine of the formula in which R represents a member selected from the group consisting of a hydrogen, a substitutedand an unsubstituted hydrocarbon radical, and R a member selected from the groupconsistingof a substituted and an unsubstituted aryl radical, in the presence of a basic condensing agent and the arylidene-amino-steroid formed as an intermediate product is hydrolyzed to yield an amino-steroid.

2. Process as claimed in claim 1, wherein the aminosteroids obtained are converted into their therapeutically useful acid addition salts.

3-. Process as claimed in claim 1 wherein the ketosteroids are. reacted with an arylmethylarnine in the presence of a basic condensing agent.

4'.-Processas claimed in claim 1, wherein an acid hydrolyzing agent is used for the hydrolysis of the arylidene amino-steroids formed.

5. Process as claimed 'in claim 1, wherein 3-ketocholestane is used as starting material.

6. Process as claimed in claim 1, wherein a member selected from the group consisting of ll-keto-tigogenin and an ester thereof is ,used as starting material.

7. Process as claimed in claim 1, wherein a member selected from the group consisting of hecogenin andan ester thereof is used as starting material.

8. Process as claimed in claim 1, wherein ll-ketoallopregnan-3,8-ol-20-ethyleneketal is used as starting material.

9. Process as claimed in claim 1, wherein an ester of 11-keto-allopregnan-3,8-ol-20-ethyleneketal is" used as starting material. V

References Cited in the file of this patent UNITED STATES PATENTS' OTHER REFERENCES Hershberg et al.: Chem. & Ind., vol..45- (November 8 1958) pages 1 4-77 and 1478. V 

1. PROCESS FOR THE MANUFACTURE OF AMINO-STEROIDS, WHEREIN A KETO-STEROID IS REACTED WITH AN AMINE OF THE FORMULA 